HIP/PAP stimulates liver regeneration after partial hepatectomy and combines mitogenic and anti‐apoptotic functions through the PKA signaling pathway

MT Simon, A Pauloin, G Normand, HT Lieu… - The FASEB …, 2003 - Wiley Online Library
MT Simon, A Pauloin, G Normand, HT Lieu, H Mouly, G Pivert, F Carnot, JG Tralhao
The FASEB journal, 2003Wiley Online Library
ABSTRACT The HIP/PAP (= human Reg‐2) C‐type lectin encoding gene is activated in
primary liver cancers. In normal liver, the protein is undetectable in normal mature
hepatocytes and found only in some ductular cells, representing potential hepatic progenitor
cells. The aim of this study was to examine the consequences of human HIP/PAP expression
in the liver of transgenic mice. We demonstrated that HIP/PAP stimulated liver regeneration
after partial hepatectomy. To further investigate the enhanced liver regeneration observed in …
Abstract
The HIP/PAP (=human Reg‐2) C‐type lectin encoding gene is activated in primary liver cancers. In normal liver, the protein is undetectable in normal mature hepatocytes and found only in some ductular cells, representing potential hepatic progenitor cells. The aim of this study was to examine the consequences of human HIP/PAP expression in the liver of transgenic mice. We demonstrated that HIP/PAP stimulated liver regeneration after partial hepatectomy. To further investigate the enhanced liver regeneration observed in vivo, primary cultures of hepatocytes were used to evaluate the mitogenic and anti‐apoptotic properties of HIP/PAP. HIP/PAP increased hepatocyte DNA synthesis and protected hepatocytes against TNF‐α plus actinomycin‐D‐induced apoptosis. HIP/PAP anti‐apoptotic effects against TNF‐α were clearly demonstrated when protein kinase A activity was specifically inhibited by KT5720, and HIP/PAP stimulated PKA‐dependent phosphorylation of the proapoptotic Bad protein at Ser‐112, suggesting that HIP/PAP may compete with cAMP to stimulate PKA activity. Overall, our results led us to propose a new role for a C‐type lectin, HIP/PAP, as a hepatic cytokine that combines mitogenic and anti‐apoptotic functions regarding hepatocytes, and consequently acts as a growth factor in vivo to enhance liver regeneration.—Simon, M.‐T., Pauloin, A., Normand, G., Lieu, H.‐T., Mouly, H., Pivert, G., Carnot, F., Tralhao, J. G., Bréchot, C., Christa, L. HIP/PAP stimulates liver regeneration after partial hepatectomy and combines mitogenic and antiapoptotic functions through the PKA signaling pathway. FASEB J. 17, 1441–1450 (2003)
Wiley Online Library